Field of the Invention
The present invention relates to a rack and pinion type of rotary actuator that causes a rotary shaft to be rotated by reciprocating motions of a first piston and a second piston.
Description of the Related Art
A rack and pinion type of rotary actuator, for example, is equipped with a cylinder main body through which a first cylinder hole and a second cylinder hole that extend mutually in parallel are formed to penetrate. A first piston is arranged for displacement along an axial direction in the first cylinder hole, and a second piston is arranged for displacement along an axial direction in the second cylinder hole. A first rack is provided on the first piston and a second rack is provided on the second piston. In a state of facing one another mutually, the first rack and the second rack are enmeshed with a pinion, which is provided on a rotary shaft.
Further, end covers are disposed on opposite end surfaces of the cylinder main body. A first port and a second port through which a working fluid flows are formed in one of the end covers. In addition, by an action of the working fluid, the first piston and the second piston are displaced in opposite directions to each other, whereby a table, which is provided on the rotary shaft, can be made to rotate (for example, see Japanese Laid-Open Patent Publication No. 2008-157289).